We present results from successful implementation of long-term (>10 seconds) real-time integration of acceleration to measure position. We evaluated two analog circuit designs for double integration of an acceleration signal. Our circuit design features three high-pass filters and two first order integrators, leading to a critically damped double integrator. The second design we have implemented is a second order underdamped integrator reported in the literature. Accuracy of both circuits in sensing position based on only accelerometer readings was experimentally evaluated by comparison with encoder readings. We conclude that a critically damped double integrator coupled with an accelerometer is well-suited for frequency domain system identification, thanks to reliable position measurement capability with minimal interference to system dynamics.